Induction heating apparatus



Aug. 14, 1956 w ow ET AL 2,759,086

INDUCTION HEATING APPARATUS 2 Sheets-Sheet 1 Filed Oct. 8, 1953 A 770EMF! Aug. 14, 1956 W, ow ET AL 2,759,086

INDUCTION HEATING APPARATUS 2 Sheets-Sheet 2 Filed Oct. 8, 1953 7 3 WWWM 5 c m My s A L w W 6 z ,N v 6 2 States Paten rnnucrrosr HEATINGAPPARATUS Theodore W. Kalhow, Chicago, Elk, and Lester 0. Reichelt, St.Paul, Minn, assignors to Western Electric ilompany, Incorporated, NewYork, N. Y., a corpora tion of New York Application Uctober 8, 1953,Serial No. 384,812

8 Ciaims. ((Zl. 219--1.43)

This invention relates to induction heating apparatus and moreparticularly to a sectional induction heating coil structure andmechanism for positioning the coil.

It is an object of the present invention to provide a sectionalinduction heating coil structure having movable coil elements andsupporting conductors therefore provided with cooperating portions forestablishing a good electrical connection therebetween.

It is a further object of the invention to provide an adjustable coilsupporting mechanism for positioning the coil in a predeterminedoperative position relative to the work.

One type of apparatus illustrating certain features of the invention mayinclude a split induction heating coil having two sections which arepivotally mounted at one end to the upper end of a pair of elongated,vertically disposed connector members for movement from an open positionto a closed position encircling a portion of the article to be heatedand in which closed position the other ends of the coil sections engageeach other and have means for releasably clamping them together.Adjacent the pivoted ends, the coil sections each have a pair ofdiverging surfaces which engage conforming diverging surfaces formed onthe upper ends of the connector members and cooperate therewith forestablishing a good electrical connection and for limiting the movementof the coil section to their predetermined closed position. The lowerends of the elongated connector members are connected to terminals of ahigh frequency current source and to an adjustable plate which isconnected to the upper end of three turn buckles which in turn arearranged in triangular relation to each other and have their lower endssupported on a stationary frame whereby in response to adjusting theturnbuckles, the adjustable plate may be tilted to impart lateralmovement to the upper ends of the connector members and the coil toaccurately position said coil relative to a predetermined vertical axisalong which the article to be heated is raised to operative position.

Other objects and advantages will become apparent from the followingdetailed description thereof and the accompanying drawings illustratinga preferred embodiment of the invention, in which Fig. 1 is afragmentary vertical sectional elevational view of an induction heatingapparatus;

Fig. 2 is an enlarged plan view of the induction heating coil forming aportion of the apparatus;

Fig. 3 is a side elevational view of the induction heating coil and aportion of the structure associated therewith;

Figs. 4 and 5 are vertical sectional views taken on the lines 4-4 and5-5 of Fig. 2;

Fig. 6 is an elevational view of a portion of the coil supporting andadjusting mechanism of the apparatus looking in the direction of arrows66 on Fig. 1; and

Fig. 7 is a plan sectional view taken on the line 7-7 of Fig. 1.

The present apparatus is designed to heat electronic tubes ltl of themagnetron type to effect the brazing of a component 11 to a component 12thereof. The juncture of the components 11 and 12 is positioned withinthe induction heating coil 15 and has a ring of brazing material (notshown) interposed therebetween to effect the bonding of the componentsduring the brazing operation. The tube 10 is supported in a holder 17mounted on the upper end of a piston 18, which is movable within astationary cylinder 19 of a hydraulic actuator for raising the holder 17from a lower position for loading and up: loading the tube lit thereinto an upper position as shown in Fig. 1 for supporting the tube inoperative position within the induction heating coil 15. An annulartable 21 supported on the upper end of the stationary cylinder 19 isadapted to cooperate with a vertically movable cylindrical glass housing22 to form a chamber enclosing the coil 15 and the tube 10 and intowhich a brazing gas may be flowed prior to the brazing operation. Thehousing 22 has means connected at its upper end for raising and loweringit.

The component 11 of the magnetron tube 10 has an end portion 23 which islarger than the juncture of the components 11 and 12 being brazed and inorder to permit the movement of the magnetron to its operative orbrazing position Within the coil 15 the coil is made in two sectionswhich are disposed in their open position during the upward movement ofthe magnetron and are moved to their closed position after the magnetronhas reached its brazing position.

The induction heating coil 15 comprises a pair of metal elements orsections 25 (Fig. 2) supported on the upper ends of a pair of verticallydisposed metal connector members 26 insulated from each other by a stripof insulation 27 and having lugs 28 at their lower ends connected toterminals 29 of a high frequency current generating device 30. The coilelements 25 are pivotally mounted at their rear ends for oscillatablemovement about pins 31 to and from an open position (not shown) and aclosed position shown in Fig. 2. The coil elements 25 are in the form ofelongated flat plates of irregular shape having recesses 32 adjacent theforward ends thereof which recesses cooperate to form an opening forreceiving portions of the components 11 and 12 of the magnetron tube 10therein. The forward end portions of the coil elements 25 have V-shapedconvex and concave surfaces 33-34 adapted to engage each other in closedposition, and the ends of the coil elements are adapted to bereleaseably held in tight engagement with each other by a clampingmember 35 pivotally connected to one of the coil elements at 36 andhaving a threaded clamping member 37 adjustably mounted thereon andengageable with the other coil element for clamping the forward ends ofthe elements together.

The coil elements 25 are spaced apart from each other except at theirforward ends and the rear portions there of are provided with flat lowersurfaces 42 which engage and are supported by the upper surfaces 43 ofthe connector members 26 for horizontal oscillatable movement thereonabout the pins 31 which fit within cylindrical apertures in the coilelements. Adjacent the pivot pins 28 and extending forwardly therefrom,the coil elements 25 are provided with flat sloping surfaces 44 indiverging relation to the surfaces 42 thereof, which surfaces 44 areadapted to engage conforming sloping surfaces 4-6 formed on the lowerside of a pair of blocks 47.

The blocks 47 each have a pair of apertures 4-8 for receiving a pivotpin 31 and a second pin 49. The pins 31 and 49 are adjustably mounted inthe upper portion of counterbored threaded apertures 50 in the upperends of the connector members 26 and have lower threaded portionsengaging the threaded lower portions of the apertures 5d. Heads 51formed on the pins 31 and 49 have flat portions 52, by means of whichthe pins may be rotated and have shoulders 53 engageable with the flatupper surface of the blocks 47. Slots extending inwardly from the endportions of the block 4-7 and intersecting the apertures 48 therein formbifurcations 56 which may be moved toward each other by screws 57''passing through one of the bifurcations and threadedly engaging theother for clamping the pins 31. and 49 to the block 47 in adjustedposition.

Recesses 58 in the coil elements 25 provide clearance for the pins 49and permit free oscillatable movement of the coil elements to and fromtheir open and closed positions. With the coil elements 25 in theirclosed position (Fig. 2), the adjustable pins 31 and 4'9 re adjusted toposition the blocks 47, with the sloping surfaces 46 thereof in tightengagement with the sloping surfaces 44 of the coil elements 25, afterwhich the screws 56 are tightened to securely clamp the pins 31 and 49in fixed position. The surfaces 46 of the blocks 47 and the surfaces 43of the connector members 26 are in converging relation to each other andconform to and are engagement with the surfaces 44 and 12, respectively, of the coil elements 23 and serve to establish a tight electricalconnection between the terminal connector members 26 and the coilelements 25. The arrangement of the pairs of converging conformingsurfaces on the coil elements 25 and on the blocks 47 and connectorelements 26 readily permits the movement of the coil sections 25 to andfrom their open and closed position.

Diverging surfaces 63 formed on the rear end portions of the coilsections 25 are engageable with the strip of insulating material 2'7 andserve as stops to limit the outward movement of the coil sections 25 totheir open position. The diverging surfaces 4-2 and 4-4 of the coilelements 25 and the conforming cooperating surfaces 43 and 46 onopposite sides of a vertical central plane through the center of thecoil and the strip 27 are disposed in opposite directions and arearranged to stop the movement of the coil elements in a predeterminedclosed position. The upper portions of the rear ends of the coilelements are cut away at 61 to provide clearance for the movement of theend portions of the coil elements under the blocks 4-7 during thetraverse of the coil elements to and from open and closed positions, andin addition thereto portions of the lower faces of the blocks 47 engagethe surfaces 61 of the coil sections and hold them against verticalmovement when the coil sections 25 are in open position and therebyprevent tilting movement of the coil sections.

It will be understood that the pins 31. and 4-9 may be adjusted to varythe position of the blocks 47 to accommodate coil sections 25 of variousthicknesses.

The connector elements 26 are secured to each other at their upper endsand to the strip of insulating material 27 therebetween by a stud 65extending through apertures in the members 26 and sheet 27 and through abushing 67 of insulating material and through washers 68 of insulatingmaterial fitting in the counterbored ends of the apertures, and a pairof lock nuts 7 threadedly engaging the opposite ends of the stud. At thelower end thereof, the connector members 26 are secured to each otherand the strip of insulating material 27 by a pair of studs 72, whichpass through apertures in the members 26 and through bushings 73 ofinsulating material therein and through apertures in a pair of bracketsor lugs '75 extending upwardly from a block '76 of insulating materialon opposite sides of the members 26. Washers 7'7 and loci; nuts 78threadedly engaging the opposite ends of the studs and the lugs 75 serveto lock the elements in tightly assembled relation to each other.

The block 76 of insulating material is secured to an adjustable plate 80by a pair of bolts 31 mounted in spaced relation to each other onopposite sides of a plane passing through the strip of insulation 27. Aportion of the plate 80 extends laterally from the block 76 and underthe terminals 29 of the high frequency current generating device 38 andhas a bolt 82 extending downwardly therefrom in said plane through thestrip 27 and in lateral spaced relation to the pair of bolts 81. Thebolts 81 and E32 are secured to the plate 89 by lock nuts 83 mounted onthe threaded lower end of the bolts, which also threadedly engagesleeves 86 and lock nuts 87. Bolts 83, fixed to a base plate 39, havetheir upwardly extending end portions threadedly engaging the sleeves3-6 and loci; nuts i The bolts 81, 82, and 88 and the sleeves 86 andloclt nuts 37 and 89 associated therewith form threaded adjustingmembers or turnbuckles 91 which are disposed in triangular relation oneto another and may be manipulated to tilt the adjustable plate Si) andlaterally adjust the upper end of the connector members 26 and the coill5 thereon to accurately position the coil and the opening therein in apredetermined position of alignment relative to the components 11 and 12of the magnetron tube It The base plate 39 is supported on a block 93and is secured thereto by a pair of bolts 94 which pass throughapertures 95 in the base plate and engage threaded apertures in theblock 93. The apertures 95 in the base plate are large enough to permita limited horizontal movement of the plate on the block 93. The block 93is secured to a rigid channel iron frame member 98 by a plurality ofscrews 99 and forms a rigid stationary support for supporting the baseplate 89, the adjustable plate 243 and the connector members 27 and thecoil 15 carried thereby. The channel member 98 is part of a frameencircling the device 30 and is supported by legs or other suitablemeans in spaced relation to the floor or a base (not shown) on which thecurrent generating device 38 and the cylinder 19 are also mounted. Thelaterally projecting lugs 23 on the connector members 26 are secured tothe terminals 29 on the current generating device 39 by a plurality ofbolts lllll passing through the lugs 28 and the terminal 29 and intothreaded engagement with the blocks 1G2 below the terminals. A pluralityof cooperating wedge members 103 of insulating material are mounted onthe adjustable plate 80 in engagement with the blocks 102 to support theterminals 29 form a relatively rigid connection between the terminalsand the plate.

The coil 15 and the connector members 26 are provided with passageways119 and 112 which are interconnected by suitable conduits 115 throughwhich coolant is circulated to cool the coil and the connector membersduring the brazing operation.

From the foregoing it will be seen that the two elements 25 of the coil15 are readily moved to and from open and closed positions and that themovable diverging surfaces 4-2 and 44 on the coil sections cooperatewith the stationary diverging surfaces 43 and 46 on the members 26 and47 to accurately stop the coil elements in their closed position andalso establish a good electrical connection between the connectormembers 26 and the coil elements while the forward end portions of thecoil elements are clamped in tight engagement with each other by theclamping member 37 it will also be seen that the plate 89 may beadjusted on the block d3 to roughly align the core relative to themagnetron and that by adjusting the turnbuckles 91 the plate 89 and theconnector elements 26 may be tilted to obtain a fine lateral adjustmentof the coil 15 for accurately aligning the opening therein with respectto the components 11 and 12 of the magnetron tube 10.

It is to be understood that the above-described arrangements are simplyillustrative of the application of the principles of this invention.Numerous other arrangements may be readily devised by those skilled inthe art which will embody the principles of the invention and fallwithin the spirit and scope thereof.

What is claimed is:

1. An inductor for a high frequency induction heating apparatuscomprising a pair of adjacent connector members connectible to a sourceof high frequency current, a pair of movable coil elements, meanspivotally supporting said coil elements at one end thereof on sa1dconnector members for movement to and from closed and open positions,said coil elements being shaped to encircle an article to be heated whenin said closed position and having conforming surfaces on the other endsthereof engageable with each other, means at said other ends of saidcoil elements for releasably securing said ends together in tightengagement with each other, said coil elements each having a pair ofdiverging surfaces ad acent said one end, and means on said connectormembers forming conforming diverging surfaces engageable with theconverging surfaces on said coil elements and forming Wedging contactstherewith when said elements are in closed position to establish a tightelectrical connection between the terminal connecting members and thecoil elements.

2. An inductor for high frequency induction heating comprising a pair ofadjacent connector members connectible to a source of high frequencycurrent and hav ing fiat coplanar supporting surfaces thereon, apair ofmovable coil elements, means pivotally supporting said coil elements atone end thereof on said connector members for movement on said flatsurfaces thereof to and from closed and open positions, said coilelements being shaped to encircle an article to be heated when in saidclosed position and having conforming surfaces on the other ends thereofengageable with each other, means at said other ends of said coilelements for releasably securing said ends together in tight engagementwith each other, said coil elements each having a flat surfaceengagea-ble with the fiat surfaces of said connector members and havinga sloping surface in diverging relation to said flat surface, and meanson said connector members having sloping surfaces engageable with thesloping surfaces on said coil elements when said elements are in closedposition to stop the coil elements in a predetermined closed positionand in cooperation with said fiat surfaces on said connector elements toform a wedging engagement with the coil elements for establishing atight electrical connection between the connector members and the coilelements.

3. An inductor for a high frequency induction heating apparatuscomprising a pair of connector members connectible to a source of highfrequency current and having fiat coplanar supporting surfaces thereon,a pair of movable coil elements having fiat surfaces engageable with theflat surfaces of said connector members and having sloping surfaces indiverging relation to said flat surfaces to form wedge portions on saidelements, means pivotally supporting said coil elements at one endthereof on the flat surfaces of said terminal members for movement toand from closed and open positions, said coil elements having portionsshaped to encircle an article to be heated when in said closed positionand having conforming surfaces on the other ends thereof engageable witheach other, means at said other ends of said coil elements forreleasably securing said ends together in tight engagement with eachother, a pair of blocks having sloping surfaces, and adjustable meansfor fixedly supporting said blocks on said connector members with thesloping surfaces on the blocks in spaced and diverging relation to saidflat surfaces on the connector members and in positions to engage thesloping surfaces on said coil elements and stop the movement thereof ina predetermined closed position, the sloping and iiat surfaces of thewedge portions of said elements on said coil eiements cooperating withthe fiat and sloping surfaces on said connector members and said blocksfor establishing a wedging engagement therewith and a good electricalconnection between the connector members and the coil elements.

4. In an induction heating apparatus, the combination of a pair ofadjacent elongated connector members having means at their lower endsconnectible to a source of high frequency current, means for securingsaid members in spaced and insulated relation to each other for movementtogether, a coil having ends supported on the upper ends of theconnector members and electrically connected thereto and having anopening for receiving therein in a predetermined position an article tobe heated, an adjustable plate, means for securing the lower ends of theconnector members onto said plate in insulated relation thereto forsupporting the connector members and the coil thereon, a stationary baseplate, and means comprising three individually adjustable devicesinterconnecting said plates and arranged in spaced and triangularrelation to each other for adjustably supporting the adjustable piateand operable to effect the adjustment of the connector members and thecoil carried thereby.

5. In an induction heating apparatus, the combination of a pair ofadjacent elongated connector members having means at their lower endsconnectible to a source of high frequency current, means for securingsaid members in spaced and insulated relation to each other for movement together, a coil having end portions supported on the upper ends ofthe connector members and electrically connected thereto and having anopening for receiving therein in a predetermined position an article tobe heated, an adjustable plate, means for securing said lower ends ofthe connector members onto said adjustable plate in insulated relationthereto for supporting the connector members and the coil thereon, astationary base plate, means comprising three turnbuckle devicesinterconnecting said plates and arranged in spaced and triangularrelation to one another for adjustably supporting the adjustable plateand operable to effect the adjusting of the connector members and thecoil carried thereby.

6. In an induction heating apparatus, the combination of a pair ofadjacent elongated supporting and terminal connector members havingmeans at their lower ends connectible to a source of high frequencycurrent, means for securing said members in spaced and insulatedrelation to each other for movement together, a coil extending laterallyfrom one end of the connector members and having end portions supportedon and electrically connected to said connector members and having anopening for receiving therein in a predetermined position an article tobe heated, an adjustable plate, means for securing the other ends of theconnector members onto said plate in insulated relation thereto forsupporting the members and the coil thereon, a stationary base plate,three threaded members fixed to and extending from said adjustable platein spaced and triangular relation to each other, three threaded membersfixed to and extending from said base plate in alignment with saidthreaded members on said adjustable plate, and rotatable threadedsleeves threadedly engaging the threaded members on said plates fortilting said adjustable plate relative to said base plate to effect theadjustment of said coil and for supporting said adjustable plate inadjusted position.

7. In an induction heating apparatus, the combination of a pair ofadjacent elongated connector members having means at their lower endsconnectible to a source of high frequency current, means for securingsaid members in spaced and insulated relation to each other for movementtogether, a coil having end portions supported on the upper ends of theconnector members and electrically connected thereto and having anopening for receiving therein in a predetermined position an article tobe heated, a first plate, means for securing one end of the connectormembers to said first plate in insulated relation thereto for supportingthe members and the coil thereon, a second plate, a stationary framemember for supporting the second plate thereon for limited horizontalmovement, means for receiving said second plate in adjusted position onsaid stationary frame member,

and means comprising three individually adjustable threaded devicesinterconnecting said plates'for adjustably supporting the first plateand operable to etfect the adjusting of the connector members and thecoil carried thereby.

8. An inductor for high frequency induction heating comprising a pair ofcoil elements, a pair of members connected to the ends of said coilelements for supporting them, means pivotally mounting one of said coilelements on one of said supporting members-for movement to and fromclosed and open positions relative to the other coil element, said coilelements being shaped to encircle an article to be heated when in closedposition and having surfaces at the other ends thereof engageable witheach other, means at said other ends of said coil elements forreleasably securing said ends in tight engagement with each other, saidmovable coil element having a wedge shaped portion with a pair ofdiverging fiat surfaces at said one end thereof, and means on said onesupporting member forming diverging surfaces conforming to andcngageable with me converging surfaces on said coil element when saidelement is in closed position to establish a tight electrical connectionbetween the supporting member and the coil element.

References Cited in the file of this patent UNITED STATES PATENTS1,313,591 Ulrey July 7, 1931 2,293,049 Denneen et a1 Aug. 18, 19422,343,889 Denneen et a1 Mar. 14, 1944 2,481,008 Gagliardi et a1 Sept. 6,1949 2,537,289 Van Embden Jan. 9, 1951'

